ZnO-NiO core-shell nanowires and Ni-ZnO nanoparticle-nanowire composites have been synthesized by atomic layer deposition (ALD) and H2 thermal reduction, respectively. Grown ZnO nanowires on Si substrates by vapor transport method were used as templates for the growth of NiO layers. In order to prevent interfacial interaction between deposited NiO and ZnO nanowires templates by the reaction at low temperature and to precisely control the thickness of NiO layer, ALD technique was suitably employed to form the ZnO-NiO core-shell nanowires. All surface area of ZnO nanowires was completely and uniformly covered by amorphous NiO layers at low temperature of 130 degrees C. The Ni-ZnO nanoparticle-nanowire composites were achieved by the thermal reduction of the ZnO-NiO core-shell nanowires at H2 atmosphere. The density of Ni nanoparticles on ZnO nanowires was roughly related to the pre-deposited NiO thickness and the inter-diffusion of Ni into the ZnO nanowire was not observed.